What is Dolby Atmos? How can you have it in your Home Theatre?

Posted by Scott Davies on

Dolby Atmos in the Movie Theatre

Until recently, sound at the movies has been mixed in a method for the cinema to make it sound the way it would in home. The mixer set a specific number of channels to designated speakers. At home, a 5.1 mix may create a surround sound effect to the rear speakers. In the cinema, the same principles would apply.

Dolby Atmos has changed this dynamic as it is bases on audio objects rather than specific audio channels. You must be thinking what is an audio object? Well an audio object is any particular sound event heard in a movie. An example of this would be a car explosion or someone yelling. Dolby Atmos is then able to determine exactly where these sounds should be coming from regardless of the amount of speakers in a system.

Moreover, Dolby Atmos technology mixes and renders each sound in real-time and in a way that is customised to the speaker configuration.

This produces a far more seamless and realistic surround sound effect. Your ear's may tell you that the helicopter swoosh is coming from the left at 10 o’clock rather than being surrounded by the clamor of helicopter rotors from one side of the theatre. Early versions of surround sound promised this level of precision, but never before have they been able to be this accurate.

In addition, Dolby Atmos adds the extra dimension of height to the soundtrack. The helicopter rotor swoosh now comes from overhead as well as from the left from a certain degree. This adds to the realistic nature of the Dolby Atmos sound environment.

Thus, Dolby Atmos adds more than just additional channels by eliminating the concept altogether. Rather than instructing the program to send “this sound to left-front speaker,” the designer programs the Atmos system to position a sound “object” in a designated area, such as “front corner, three quarters up the wall.”

Each theatre utilises an Atmos decoder that interprets the location and number of speakers, determines the location metadata from the sound feed and sends the sound to the precise location predetermined by the sound designer. Dolby Atmos technology can handle 128 specific sound objects at a time per scene.

In Home

The release of Dolby Atmos created an expectation that the technology would be available for home theatre systems eventually. However, Dolby used a marketing strategy which included holding back release of the home system until more cinemas used Atmos. This way, more potential consumers had a chance to experience the difference creating a buzz for the product prior to release.

Implementing Dolby Atmos in home involves a new receiver or pre-amp that processes Atmos decoding and also additional speakers. However, an existing Blu-ray player along with your current hdmi cables will suffice. The Atmos metadata will work with the current HDMI specifications and current Blu-ray. Atmos will activate when it senses the compatible decoder. In addition, Atmos will work with non-Atmos decoding equipment. For instance, a Blu-ray disc without Atmos programming will still play on other equipment, just without the additional feature.

Because Dolby Atmos is object based rather than speaker based, in-home Atmos works the same. The new receiver detects the speakers and their locations, and with some additional information input by the owner, the receiver will create a custom surround mix based on the equipment and room.

The Equipment

Dolby Atmos is now supported on the new '79 series Yamaha Receivers from the RX-V1079 and up.

At a minimum, an in-home Atmos system takes a 5.1.2 configuration. This is five directional speakers with one subwoofer and two speakers on the ceiling. For systems that already work with 5.1 sound, only an additional two ceiling speakers and an Atmos receiver is needed to complete the setup.

For those interested, Dolby recommends a complete home setup that is 7.1.4, with four ceiling speakers. The in-home version of Dolby Atmos can support up to a 24.1.10 setup; however, this may be more than the average consumer wants or needs.

With the new technology, processing and decoding, a new receiver or pre-amp is mandatory; however, many of the latest model receivers come with Atmos capabilities included. In addition, because many consumers remain sceptical about speakers on the ceiling or don't have the ability to install them in a rental property, Dolby has added an innovation that gives the upward-firing drivers in stand-mounted or floor speakers the ability to bounce sound off of the ceiling. This creates the impression of sound coming down from the ceiling.

In order to produce this more realistic sound, Dolby Atmos has three specific elements in addition to more speakers, including the ceiling speakers. These are:

  • Object Audio: mono or stereo channels that have dedicated surround sound panning. These channels remain individual rather than together in a bed.
  • Bed Audio: these channel based stems remain in essence identical to earlier surround formats, and the individual channels remain static in the bed.
  • Metadata: this includes surround metadata for the object audio in addition to other metadata.

Atmos can surround pan the objects along all three axes: left/right, front/rear, and up/down. The metadata defines the position of the objects as well as their size. Atmos can render the objects up to 128 different elements (118 objects plus 9.1 bed channels) up to the maximum 64 speaker feeds in commercial theatres.

Along with the home market, Dolby has plans to market Atmos for smartphones and tablets with the immersive audio projected through the headphones. Most likely, Atmos will come built into smartphones and tablets in both the hardware and apps. The hardware-based versions will produce better sound; however, an app allows the user to experience it without waiting for a phone upgrade.

Content

Without movies and other content becoming readily available in the retail marketplace, most Dolby Atmos hardware will have wait for the content to catch up. Transformers: Age of Extinction has been named as the first blu-ray which will include a Dolby Atmos Sound Track, with more to follow in the near future.  Dolby has also announced that it is in works to bring Atmos to Netflix and other Internet streaming services as well.

Once the content becomes more common, home theatre buffs will most likely join the early adopters, which in turn will bring Atmos to the larger markets. This may well push price down as quality continues to rise benefiting the in-home theatre segment of the entertainment market.

We hope we were able to clear up some of your questions about the new Dolby Atmos Standard and as always if you have any questions be sure to ask as we are here to help.

Yamaha have bundled together a full Dolby Atmos Home Theatre Package which contains all the components you need to enjoy Dolby Atmos at home for a great price.

This Kit Includes:

  • 1x Yamaha RX-V1079 AV Receiver
  • 2x Yamaha NS-555 Floorstanding Speakers
  • 1x Yamaha NS-C444  Centre Speaker
  • 2x Pairs of Yamaha NS-333 Book Shelf Speakers
  • 1x Yamaha YST-RSW300 Subwoofer
  • 1x Pair of Yamaha NS-IC600 In-Ceiling Speakers

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